99 SS Power loss hesitation at partial throttle.

This is a discussion on 99 SS Power loss hesitation at partial throttle. within the General Help forums, part of the LSx Technical Help Section category; Hello all, I spent the better part of the morning searching the forum and I haven't really come up with ...

99 SS Power loss hesitation at partial throttle.

Hello all, I spent the better part of the morning searching the forum and I haven't really come up with anything conclusive so I figured I'd ask some questions.

I have a 99 SS convertible, about 92k miles, has the SLP whisper lid + K&N, and MAF screen removed, other then that it is stock.

I have only owned this car since the 70k mark, but as far as I recall I have always had some varying degree of this problem, which is:

While accelerating, there seems to be a throttle range where the car sort of "falls on it's face", loses power, or has a hesitation, depending on how you want to classify it.

After reading other posts on the forum, I guess it could be an RPM range, where it will accelerate hard, then hesitate, then take back off again at a higher RPM, I am going to do some more testing tonight, but usually to compensate for the hesitation I will put more foot into it.

Basically to me it seems like at 0-30% throttle it accelerates fairly well, at 30%-60% it actually seems to accelerate slower or with less power, and then WOT it seems fine.

I have recently replaced spark plugs and fuel filter and it made no difference at all, if anything, it is more noticeable.

had a couple of buddies have this problem, myself included. these cars have a tendency of fuel pumps going out, nothing major and you can replace it yourself. If I were you, i'd make sure first that I was getting spark, then second check the pressure at the fuel rail.

I've been troubleshooting a similar problem in my track car. Its a 944 Porsche, but I'm running an LS1 out of an 01CamaroSS. My problem was hesitation at partial throttle as you described. It was good below and above that throttle position. I recently got it working 100% again. The last two things I cleaned/checked are as follows: I took out the MAF sensor (still has screen) and used electronics aerosol cleaner to spray the elements. This was just to make sure the MAF was clean. Then i replaced the plugs. The old plugs (ACDelco) had .070" gap, whereas the new plugs i bought (again ACDelco) are supposed to be gapped at .040". After this MAF and plugs work, the engine hesitation was gone at partial throttle. I know my car is a lot different than most stock LS cars, but I hope this helps somebody.

TPS

Something else to look at is the throttle postion sensor but you will need a scan tool.Tps sensors are bassically a rotary potentiometer that varies ouput based on postion may have a bad spot. Or like the other guys say about the maf screen and having gremlins.